Highly sensitive glucose biosensor based on CF4-plasma-modified interdigital transducer array (IDA) microelectrode

A glucose biosensor with superior accuracy and sensitivity was successfully developed based on an interdigital transducer array (IDA) microelectrode. The IDA microelectrode was prepared by a photolithography procedure with sputter coated thin layers of both gold and SiO2, followed by tetrafluoromethane (CF4) plasma treatment. The enzymatic interactions between glucose and the reactants were monitored by cyclic voltammetry method to determine the blood glucose concentration. The surface properties of the developed glucose biosensor were characterized by electron spectroscopy for chemical analysis (ESCA), atomic force microscopy (AFM), and surface wettability. The correlations between the results of surface analyses and the current responses indicated that the CF4 plasma facilitated both the exposure of gold layer underneath the protection layer and the raise of surface hydrophobicity, and therefore the enhancement of the current responses. The developed IDA-microelectrode-based glucose biosensor showed particular precision and excellent reproducibility in measuring glucose concentration under the presence of common interferences and in real human blood measurements. Moreover, the IDA microelectrodes displayed a sensitivity of 0.13 μA/(mg/dL) which is much higher than commercially available products.